Photoelectric sensors have the advantages of high accuracy, fast response, non-contact, simple structure and the like, and are widely applied in detection and control. For instance, the photoelectric sensors may be applied in the aspects of smoke dust monitors, bar code scanning guns, product counters, photoelectric smoke alarms, etc.
The photoelectric sensors comprise thin-film transistors (TFTs) and photodiodes. The photodiodes receive light and convert optical signals into electrical signals. The TFTs control the reading of the electrical signals.